A few meat processing plants used compressed air to remove grey matter from animal skulls, and some did not provide adequate PPE to their workers. Several people started to show unique neurological symptoms that seemed to correlate with years of exposure to aerosolized pig brains. One person that I know of sued Hormel in 2008, and the lawsuit was dismissed with prejudice in 2009.

I've always wondered if the case had merit and we just did not have sufficient medical knowledge/techniques at the time to investigate the source, of if someone read about prions and self-diagnosed.

https://www.austindailyherald.com/2009/02/hormel-qpp-lawsuit...